IR 05000397/1994010
| ML17290B056 | |
| Person / Time | |
|---|---|
| Site: | Columbia  |
| Issue date: | 03/15/1994 |
| From: | Ang W NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION V) |
| To: | |
| Shared Package | |
| ML17290B055 | List: |
| References | |
| 50-397-94-10, GL-89-10, NUDOCS 9403310087 | |
| Download: ML17290B056 (23) | |
Text
U. S.
NUCLEAR REGULATORY COMMISSION REGION V
Report No.:
50-397/94-10 Docket No.:
50-397 License No.:
NPF-21 Licensee:
Washington Public Power Supply System P. 0.
Box 968 3000 George Washington Way Richland, Washington
'h Facility Name:
WNP-2 Inspection at:
WNP-2 Site near Richland, Washington Inspection conducted:
February 14 through 18, 1994 Inspectors:
C. Hyers, Reactor Inspector, Region V
Approved by:
3 ir~
W. P. Ang, Chief, Reactor Safety Branch Date Signed Ins ection Summar
Ins ection durin the eriod Februar
18 1994 Re ort No. 50-397 94-10 d:
A routine announced inspection of open items from previous NRC inspections of the licensee's program for Generic Letter (GL) 89-10,
"Safety-Related Hotor-Operated Valve Testing and Surveillance,"
was conducted during the week of February 14 through 18, 1994.
Temporary Instruction 2515/109 and Inspection Modules 92701 and 92702 were used as guidance during the inspection.
f Safet Issues Hang ement S stem SIHS Item:
SINS Issue Number GL 89-10 was updated to reflect this TI 2525/109 Part
inspectio Results:
General Conclusions and S ecific Findin s:
The licensee has corrected most of the previous weaknesses in their Generic Letter '89-10 program.
Additional review of valves which are susceptible to pressure locking needs to be performed.
Si nificant Safet Matters:
None.
Summar of Violation or Deviations:
None.
0 en Items Summar
New Open Items:
None Previous Open Items CLOSED During This Inspection; 91-16-01 91-16-03 91-16-07 91-16-09 91-16-10 91-16-11 91-16-12 93-23-01 93-23-02 93-23-03 FOLLOWUP FOLLOWUP FOLLOWUP VIOLATION FOLLOWUP FOLLOWUP FOLLOWUP VIOLATION VIOLATION FOLLOWUP MOVs Excluded From the GL 89-10 Program Design Basis Review Not Complete Differential Pressure/Flow Testing Degraded Spring Pack Not Reported GL 89-10 Schedule Control of MOV Switch Settings HOV Diagnostic Data Untimely Test Data Evaluation Failure to Write a PER Applicability of HOVATS ER-,5.2 Previous Open Items Remaining OPEN Following This Inspection:
93-23-04 FOLLOWUP Pressure Locking and Thermal Binding 93-201-01 VIOLATION Service Water System Valve Hammering Previous Open Items Not Reviewed During This Inspection:
91-16-02 91-16-04 91-16-06 91-16-08 91-16-13 91-16-14 DEVIATION DEVIATION FOLLOWUP FOLLOWUP FOLLOWUP FOLLOWUP Failure to Meet GL 89-10 Commitments Inadequate HOV Motor Torque Switch Setting and Sizing Calculations Periodic Verification HOV Inservice Testing GL 89-10 Supplement 3 Recommendations
Details PERSONS CONTACTED Washin ton Public Power Su
S stem
- S. Berry, HOV System Engineer
- B. Evans, Maintenance Engineer
- H. Flasch, Director of Engineering
- C. Foley, Technical Specialist, Licensing
- H..Grindel, Power Systems Supervisor
- P. Harness, Hechani'cal Design Engineering Manager
- T. Hoyle, Valve Programs Lead Engineer
- V. Parrish, Assistant Managing Director, Operations
- M. Reis, Principal Engineer
+G. Smith, Operations Division Manager / Acting Plant Manager
- R. Webring, Technical Division Manager Others
- D. Froulx, NRC, Resident Inspector The inspector also held discussions with other licensee and contractor personnel during the course of the inspection.
- Denotes those attending the exit meeting'.
FOLLOWUP OF PREVIOUS OPEN ITEMS (92701,92702)
CLOSED Followu Item 91-16-01 HOVs Excluded From the GL 89-10 Pro ram Ori inal Followu Item During a previous NRC inspection, the inspector had found instances where some HOVs in safety related systems had been excluded from the licensee's GL 89-10 program scope without documented justification.
The licensee committed to review all safety related HOVs that had been excluded from the GL 89-10 program and provide documented justification.
Licensee Actions "on this 0 en Item The licensee contracted an independent review of the GL 89-10 program including a review of all HOVs excluded from the scope of the program.
The review was completed 6/ll/92.
Mechanical Engineering Standard HES-9 was issued on 5/12/92 which contained the conditions under which an HOV could be removed from the HOV program during the performance of the design basis review.
Technical Memorandum TH-2028, Revision 1,
was issued 9/9/93 to document the basis for exclusion of HOVs from the licensee's progra Observations Durin this Ins ection The inspector reviewed the licensee's contractor report No. L106-92-03.003, dated June 11, 1992; technical memorandum TH-2028, Revision 1,
dated September 9,
1993; and Hechanical Engineering Standard HES-9, Revision 0, dated Hay 12, 1992.
The inspector selected five HOVs which had been excluded from the program and found the documented justification to be adequate.
Conclusions The inspector found that the licensee had adequately justified and documented HOVs excluded from their program consistent with the recommendations of GL 89-10.
This item is closed.
I b.
CLOSED Followu Item 91-16-03 Desi n Basis Review Not Com lete Ori inal Followu Item During a previous NRC inspection, the inspector had found four areas of weakness in the licensee's GL, 89-10 program for conducting des,ign basis reviews for HOVs.
(1)
Flow and temperature effects were not addressed.
(2)
Worst case differential pressure was not determined from a thorough review of all applicable service conditions.
(3)
Haximum opening differential pressure was not determined for HOVs with both an open and close safety function.
The maximum closing differential pressure was used for both operating directions.
(4)
For HOVs with a safety function in only one direction (i.e.
opening or closing),
oper ation in the non-safety direction was not evaluated to assure that it would not damage the HOV or affect subsequent safety related operation.
The licensee had committed to more fully address these areas of weakness in their program.
Licensee Actions on this 0 en Item The licensee revised Hechanical Engineering Standard HES-9,
"Hotor
. Operated Valve Design Basis Review," to include instructions to address each of the noted weaknesses.
The licensee's procedure was issued on Hay 12, 1992.
Observations Durin this Ins ection The inspector reviewed applicable portions of licensee procedure HES-9, dated Hay 12, 1992.
The inspector found that additional instructions had,
been included to specifically address each of the previously noted areas of weakness.
The inspector sampled the design basis reviews for two HOVs and found that each incorporated the applicable design basis considerations required by the licensee's procedure.
Conclusions The'inspector found that the licensee had adequately addressed the
'previously noted areas of weakness in their program for conducting design basis reviews.
This item is closed.
CLOSED Followu Item 91-16-07 Differential Pressure Flow Testin Ori inal Followu Item During a previous NRC. inspection, the licensee was selectively conducting differential pressure'ests under degraded voltage conditions.
The inspectors noted that quantitative information regarding the thrust margin was not evaluated during that testing.
The inspector was concerned that the testing may not be adequate to,satisfy the recommendations of GL 89-10.
Licensee Actions on this 0 en Item The licensee initiated Problem Evaluation Request (PER)
291-441 to evaluate the quantitative test data from degraded voltage testing.
Only one HOV, RHR-48B, had been tested under degraded voltage and differential pressure.
The licensee revised their HOV Program Plan to include instructions for the quantitative evaluation of test data to determine thrust margin.
Observations Durin this Ins ection The inspector reviewed PER 291-441 and the licensee's HOV Program Plan, Revision 3,. dated February 10, 1994.
Conclusions The inspector found the licensee actions to be adequate.
This item is closed.
CLOSED Violation 91-16-09 De raded S rin Pack Not Re orted Ori inal Violation The violation concerned a failure to write a PER when spring packs in two Limitorque motor operators were unexpectedly found to be collapsed.
In their September 16, 1991, response to the Notice of Violation, the licensee committed to perform a root cause evaluation of the degraded component Licensee Actions on this 0 en Item The licensee initiated PER 291-0513 to document the degraded condition of the spring packs.
Further, the licensee initiated Material Deficiency Report (HDR) 291-0513 to evaluate the root cause of the condition.
The licensee concluded that the observed collapse of the two spring packs was due to prior misassembly..
The licensee revised their maintenance procedures to include additional'nstructions on the proper assembly of
- spring packs.
In addition, the licensee established testing of spring packs to verify preload and spring rate.
Observations Durin this Ins ection The inspector reviewed PER 291-0513 and NDR 291-0513.
The inspector reviewed licensee procedures PPM 10.2.91, Revision 0,
"HOV Spring Pack Testing,"
and PPM 10.2.44, Revision 9,
"Maintenance and Repair of Limitorque Valve Operators."
The inspector noted that the licensee had not retained the spring packs which were originally identified as collapsed.
As a result, the components were not available for specific root cause evaluation.
The licensee based their root cause determination on'n analysis of the spring design and testing of available spring packs.
Conclusions The inspector found the licensee actions to be adequate.
This item is closed.
CLOSED Followu Item 91-16-10 Generic Letter 89-10 Schedule Ori inal Followu Item During a previous NRC inspection, the licensee had not yet adequately established a schedule for the completion of their GL 89-10 program.
Licensee Actions on this 0 en Item I
The licensee submitted a supplemental response to GL 89-10, dated August 31, 1993.
The response included a description of their HOV program progress and schedule for completion.
The licensee revised their NOV Program Plan to establish a detailed schedule with testing priorities.
Observations Durin this Ins ection The inspector reviewed the licensee's NOV Program Plan, Revision 3, dated February 10, 1994.
The inspector discussed the current testing status with cognizant licensee personnel.
The inspector found that the test progress was consistent with the licensee's schedul Conclusions The inspector found the licensee actions to be adequate.
This item is closed.
" f.
CLOSED Followu Item 91-16-11 Control of MOV Switch Settin s
Ori inal Followu Item During a previous NRC inspection, the inspector identified two items for further review regarding the control of HOV switch settings
.
The first item concerned several HOVs with torque switch settings which exceeded the maximum dial setting specified by Limitorque.
Preliminary results from testing of one of the HOVs, RHR-48B, under degraded voltage conditions had indicated that the actuator motor was inadequate for the high torque switch setting.
The second item concerned the licensee's response to the findings identified in their guality Assurance Surveillance Report 2-91-009.
The audit had identified weaknesses in the control of HOV Data Sheets.
Licensee Actions on this 0 en Item The licensee initiated PER 291-441 to evaluate RHR-48B and other HOVs with torque switch settings which exceeded the maximum dial setting recommended by the manufacturer.
The licensee responded to the findings of guality Assurance Surveillance Report 2-91-009 on June 10, 1991.
Corrective actions were completed August 20, 1991.
Observations Durin this Ins ection The inspector reviewed PER 219-441 and sampled corrective action's from Surveillance Report 2-91-009.
Conclusions The inspector found the licensee's corrective actions to be adequate.
This item is closed.
g.
CLOSED Followu Item 91-16-12 MOV Oia nostic Data Ori inal Followu Item During a previous NRC inspection, the licensee had committed to evaluate recent industry testing of HOVATS diagnostic test equipment and to incorporate the results of that testing, as necessar Licensee Actions on this 0 en Item The licensee initiated PER 292-211 to evaluate HOVATS Engineering Report 5.0 which provi'ded recent guidance on the use of HOVATS diagnostic test equipment.
However, to improve their diagnostic data accuracy, the licensee revised their diagnostic equipment to incorporate direct stem thrust measurement using stem mounted strain gages, Observations Durin this Ins ection The inspector reviewed PER 292-211 and the licensee's HOV Program Plan, Revision 3, dated February 10; 1994.
The inspector found that the licensee had incorporated appropriate guidance regarding the use of HOYATS test equipment.
The inspector noted that the licensee no longer used the HOVATS method of measuring spring pack displacement as the basis for determining stem thrust.
Conclusions The inspector found the licensee's actions to be adequate.
This item is closed.
CLOSED Violation 93-23-01 Untimel Test Data Evaluation Ori inal Violation This violation concerned the lack of appropriate acceptance criteria to demonstrate design basis capability and the untimely evaluation of test data from the R6 refueling outage.
Licensee Actions in Res onse to the Violation The licensee committed to establish administrative controls to assure adequate data review prior to returning the HOV to service.
The licensee stated that sufficient data review would be performed to provide reasonable assurance of valve operability.
In addition, the licensee identified that following the R6 refueling outage, their data evaluation procedure had been revised to include extrapolation of test results to design basis conditions.
The licensee initiated PER 293-1193 to address this concern.
The licensee issued procedure PPH 8.4.77,
"HOV Design Basis Testing Preliminary Evaluation,"
on 2/23/94.
The new procedure established administrative controls by which differential pressure test data would be evaluated prior to any HOV being returned to servic I
Observations Durin this Ins ection The inspector reviewed PER 293-1193 and licensee procedure PPH 8.4.77.
The inspector reviewed a recent example of dynamic testing and found that the test procedure incorporated acceptance criteria consistent with the licensee's commitment.
Conclusions The inspector found the licensee's corrective actions to be adequate.
This item is closed.
CLOSED Violation 93-23-02 - Failure to Write a
PER Ori inal Violation This violation concerned a failure to write a PER to identify that the actual torque switch setting of 22390 lb. thrust for motor operated valve RHR-V-16A did not meet the minimum thrust setpoint requirement of 39770 lb. thrust which was specified in the revised design calculation for the HOV.
Licensee Actions on this 0 en Item The licensee initiated PER 293-1192 to address the operability of all the HOVs in the licensee's GL 89-10 program in light of revised setpoint calculations.
The licensee's evaluation identified that 9 of the HOVs would not meet the revised minimum thrust requirements established in engineering standard HES-10.
The licensee initiated PER 293-1416 to further evaluate the 9 HOVs and found all to be operable.
In their letter, dated November 29, 1993, in response to the Notice of Violation, the licensee stated that the HOV Program Plan and Engineering Instructions for HOV calculations and evaluations would be revised to require that operability be documented in those situations where programmatic feedback or new industry information identifies a potential challenge to the ability of the equipment to perform under design basis conditions.
Observations Durin this Ins ection The inspector reviewed PER 293-1192, Amendment 93-20 to Engineering Standard HES-10, and Revision 3 of the HOV Program Plan.
The inspector found that the licensee had revised engineering standard HES-10, which governs preparation of HOV setpoint calculations, to require operability evaluations to be performed in cases where previously issued thrust setpoints are revised upwar The inspector found that the licensee revised their HOV Program Plan to require documentation of equipment operability when information is received that would indicate potential challenges to the ability of the HOV to function under design basis conditions.
Conclusions The'inspector found the licensee's corrective actions to be adequ'ate.
This item is closed.
CLOSED Followu Item 93-23-03 - Measurement Error Ori inal Followu Item During a previous NRC inspection, the inspector noted that the licensee had not applied measurement error adjustment to the differential pressure test thrust data from refueling outage R6.
The inspector found that the licensee had not justified their assumption of no measurement error for dynamic test thrust data.
For design basis testing conducted during the R6 refueling outage in April, 1991, the licensee used the HOVATS 3000 system as its primary diagnostic system with the HOVATS thrust measuring device (THD) which measured spring pack displacement as the basis for thrust determination.
The licensee used HOVATS Engineering Report ER-5.2, Revision 0,
"Limitorque Actuator Open vs. Closed THD Data Analysis Procedure,"
to adjust THD static test thrust data for measurement error.
ER-5.2 identified increased thrust measurement error attributable to directional effects and rate of loading.
However, the inspector found that the licensee did not consider that ER-5.2 was applicable to THD thrust data obtained during dynamic testing.
Licensee Actions on this.O en Item Due to emerging uncertainty in the accuracy of THD thrust measurements, the licensee considered the R6 test data to be unreliable.
The licensee decided to repeat the R6 differential pressure testing later in their program using alternate methods to measure thrust.
Observation Durin this Ins ection The'inspector reviewed engineering standard HES-10 and 'found that the licensee incorporated appropriate allowances for measurement error during dynamic testing.
The inspector reviewed Revision 3 of the licensee's HOV Program Plan, dated February 10, 1994.
The inspector found that the licensee had scheduled retesting of the HOVs previously tested using the THD thrust measurement metho The licensee stated that no THD data taken during the R6 outage will be used for GL89-10 closure.
Conclusions The inspector found the licensee's action to be adequate.
This item is closed.
OPEN Followu Item 93-23-04 Pressure Lockin and Thermal Bindin Ori inal Followu Item During a previous NRC inspection, the licensee committed to complete their evaluation for pressure locking and thermal binding by December 31, 1993.
The licensee indicated that resolution of any identified problems resulting from their. evaluation would be integrated into the plant schedule after that date.
Licensee Actions on this 0 en Item The licensee completed their review of the potential for pressure locking and thermal binding and issued report WPPSS-ENT-0136 on December 28, 1993.
While no HOVs were found to have any significant potential for thermal binding, the report identified
MOVs which were susceptible to pressure locking.
The actuators for 9 of the susceptible HOVs were determined to be adequate to overcome pressure locked conditions.
Modifications to eliminate the potential for pressure locking were recommended for the remaining 8 susceptible HOVs.
The recommended modifications consisted of either drilling a hole in one of the two valve disks or installing an external vent line for the valve bonnet.
The licensee initiated PER 294-0074 on February 1,
1994, to address the current operability of the 8 susceptible valves.
On February ll, 1994, the licensee initiated a Plant Modification Record (PHR) to implement the recommended modifications.
Observations Durin this Ins ection The inspector reviewed the licensee's report WPPSS-ENT-0136, dated December 28, 1993.
The inspector found that the report was a
comprehensive evaluation of the potential for pressure locking and thermal binding.
The licensee had determined that the actuators of nine HOVs were capable of overcoming the pressure locked conditions to which the HOVs were susceptible.
For these large actuators, the inspector noted that the licensee had not evaluated the weak link of the HOV under pressure locked conditions.
The inspector was concerned valve damage may occur when unseating under pressure locked conditions.
Since the torque switch was bypassed during valve unseating, full stall thrust capability of the large actuator could be applied to the valve for a short period of time when opening under pressure locked condition,f
In response to the inspector's concern, the licensee committed to perform a weak link analysis under pressure locked conditions for all HOVs which were susceptible to pressure locking and were not inherently stall protected by design.
The inspector noted that the licensee had not tested, under pressure locked conditions, the 9 susceptible HOVs which they did not intend to modify.
The inspector found that the licensee had'nalytically justified
- the adequacy of the existing actuator based on a double-disk-area method of predicting pressure locked valve operating requirements.
The inspector found that the licensee's justification for the 9 NOVs appeared to be conservative.
However, due to the lack of industry experience in predicting operating requirements under pressure locked condition, the validity of the licensee analysis method will be reviewed in a future inspection.
Conclusions Except for additional licensee review of weak link vulnerability, the inspector found that the licensee had completed their review of the potential for pressure locking and thermal binding.
The licensee was taking action to implement modifications of 8 of the 17 valves which they had determined to be susceptible.
The licensee was not taking action to modify 9 susceptible MOVs which they considered to be capable of operating under pressure locked conditions.
This item will remain open pending review of the licensee's weak link analysis under pressure locked conditions and further review of the capability of HOVs to operate under pressure locked conditions.
OPEN Violation 93-201-01 Service Water S stem Valve Hammerin Ori inal Violation This violation involved two examples of inadequate corrective actions.
One example concerned valve hammering.
The other concerned chemistry control for the service water system.
This followup inspection addresses only the issue of valve hammering.
If the HOV actuator is not self locking, valve hammering can occur after valve closure when the actuator repeatedly responds to a continuing close signal.
The licensee had experienced valve hammering in the operation of both of the service water loop isolation valves SW-V-12A and SW-V-12B.
However, the licensee had not taken appropriate action to preclude repetition of the hammering.
Licensee Actions on this 0 en Item The licensee initiated PER 293-158 on February 10, 1993, to evaluate hammering incidents.
The licensee disassembled SW-V-12B in an attempt to determine the cause but found no problem evident in the valve assembly.
The licensee subsequently modified the control logic for SW-V-12A and SW-V-12B to remove the continuous close signal to prevent the hammerin Observations Durin this Ins ection The inspector reviewed PER 293-158 and Basic Design Change 91-0221-0A.
Conclusions The inspector found the licenseq.'s corrective actions for valve hammering to be adequate.
This item will remain open pending followup of the licensee's corrective actions for control of service water system chemistry.
m.
Previous 0 en Items Not Reviewed Durin This Ins ection At the time of the inspection, the licensee had not completed their followup actions for the following open items.
91-16-02 91-16-04 91-16-06 91-16-08 91-16-13 91-16-14 DEVIATION DEVIATION FOLLOWUP FOLLOWUP FOLLOWUP FOLLOWUP
.Failure to Meet GL 89-10 Commitments Inadequate MOV Motor Torque Switch Setting and Sizing Calculations Periodic Verification MOV Inservice Testing GL 89-10 Supplement 3 Recommendations These items will remain open.
No violations or deviations were identified.
3.
EXIT MEETING An exit meeting was conducted on February 18, 1994.
During this meeting',
the inspectors reviewed the scope and findings of the inspection.
The licensee acknowledged the inspector's findings.
The licensee did not identify as proprietary any information provided to or reviewed by the inspecto